1. Field of the Invention
This invention relates generally to a semiconductor fabrication process, and, more particularly, to associating data with workpieces in the semiconductor fabrication process and correlating the data with yield data of the processed workpieces.
2. Description of the Related Art
There is a constant drive within the semiconductor industry to increase the quality, reliability and throughput of integrated circuit devices, e.g., microprocessors, memory devices, and the like. This drive is fueled by consumer demands for higher quality computers and electronic devices that operate more reliably. These demands have resulted in continual improvements in the manufacture of semiconductor devices, e.g., transistors, as well as in the manufacture of integrated circuit devices incorporating such transistors. Additionally, reducing the defects in the manufacture of the components of a typical transistor also lowers the overall cost per transistor as well as the cost of integrated circuit devices incorporating such transistors.
During the fabrication process, various events may take place that affect the performance of the devices being fabricated. That is, variations in the fabrication process result in device performance variations. Factors, such as feature critical dimensions, doping levels, contact resistance, particle contamination, etc., may potentially affect the end performance of the device. Various tools in the processing line are controlled, in accordance with performance models, to reduce processing variation. Commonly controlled tools include photolithography steppers, polishing tools, etching tools, and deposition tools. Pre-processing and/or post-processing metrology data is supplied to process controllers for the tools. Operating recipe parameters, such as processing time, are calculated by the process controllers based on the performance model and the metrology information to attempt to achieve post-processing results as close to a target value as possible. Reducing variation in this manner leads to increased throughput, reduced cost, higher device performance, etc., which equates to increased profitability.
Semiconductor manufacturing processes, which have become increasingly more reliable and robust, may include a plurality of processing tools that cooperate with each other to process semiconductor devices, such as, microprocessors, memory devices, ASICs, etc. To verify that the processing tools are operating within acceptable parameters, it has become increasingly desirable to monitor the operating conditions of such processing tools.
During the manufacturing process, various metrology data is collected to allow automatic process control, fault detection and classification, defect identification and performance measurement. However, the data that is collected may oftentimes be inadequate for troubleshooting process defects. That is, the collected data may be inadequate to explain deviations in the yield of the processed workpieces, such as wafers.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.